Lens mount



Nov. 10, 1931. K. KRUENING LENS MOUNT Original Filed Jan.

INVENTOR.

ATTORNEYS.

Patented Nov. 10, '1931 UNITED ,STAI

KARL xnUENInG, or aamrcn, NEW YOZRItI, .ASSIGNOR'TO KOLLMORGEN or'rr04:. con- P OBATION, OF'BROQKLYN, NEW YORK, ACORCPORATION OF NEW YORKLENS noun:

'. Original application filed January 25, 1828, Serial No. 249,223.Divided and this "1929. Serial .No. 879,136.

This invention relates to mounts for lenses and has particular referenceto the mounting of projection lenses in the motionpicture industry,although of course not limited to this industry. In such a lens systemfour lenses I are usually employed, one pair being cemented together andtermed thev front-element, while the other two are usually uncementedand for descripi ive purposes will be referred '1 to herein as the rearelement. Inasmuch as these lenses must be removed from their mounts fromtime to time for cleaning purposes care must be exercised in placingthem in position again in correct relation toeach other and oftentimesthrough carelessness the lenses are reversed resulting in images of verypoor quality. t The present invention hasfor one of its objects theprovision of a construction wherein such a possibility is overcome. Inother:

words, the present invention provides aconstruction whereby the lenseswill necessarily be inserted in correct position at all times.

In the drawings accompanying this appli- 2 cation: 1 1

i v Fig. 1

section. of a lens system constructed in accordance with my invention;and

Fig. 2 is a section on the line 22 of-Fig. 1. Referring to the drawingsin detail, 1 designates the lens tube of my improved mount. The frontelement ofthis apparatus is composed of two lenses 2 and 3 which asabove mentioned and as illustrated are cemented together. Threaded intothe forward vided with a reduced portion 5 threaded ex.- ternallyasindicated at 6 and internally as indicated at'7. The retaining ring 4ispro-. vided adjacent it'souterjend with ashoulder 8 which isconveniently provided by reducing the diameter of the int point.

The lenses H within the retaining ring 4 and are slipped into the ringfrom the inner end thereof until they abut the shoulder 8. A clampingring. 9 screws into the inner end of the retaining ring 4 anda'swill beseen from the drawings clamps the lenses 2 and3 as a unit against" s aview in side elevation partly in end of the tube '1 is a retaining ring4 pro erior of the ring at this ,2 and .3 above referred to fitapplication filed July 18,

the shoulder 8 provided in the retainin' ring 4'so as to hold the lensessecurely and rmly in position.

In order that the lenses may not be re-- versed and must always beplaced in the retaming ring '4.in correct position, the interior of theretaining, ring is provided with in-. wardly extending projections orribs 10, these ribsextending lengthwise of the ring 4. The

projections or ribs *may take various forms 0 but are inwardly spacedfrom each other as appears from an inspection of Fig. 2. The lenses2'and 3 are provided in their periphery with slots 11 which are spacedunequally but correspondingly to'the spacing c5 of the projections'orribs 10 so that the lenses are necessarily placed in their correct posi-'lilOIl when'inserted in the ring 4 inasmuch as if the lenses werenotplaced-in correct position, that is reversed or otherwisedisplaced,

the grooves or slots 11 in their peripheries would not register with theprojections. or ribs 10 and it would be impossible to insert the lensesinto theretaining tube hr retaining -rmg.

The rear element of my improved construc-' tion comprises lenses 12 and18. These lenses are of a difl'erent diameter than the. front .elementand hence not interchangeable therewith. 14 designates a retaining tubethreaded so into the lens tube 1. This retaining tube is provldedinternally witha shoulder 15. The lenses 12 and'13 which as above'notedare not cemented to each other have their pe-i ripheries notched as at16. These notches are unequally spaced and cooperate with .unequallyspaced ribs 17 PIOJBCtiITg' inwardly within the retaining tube 14. Thenumber- .of no hes and ribs, or their equivalent, for the le from whichit will be evident that reversal of these two lenses is effectuallyprevented. The lenses are heldin position in the re taming tube 14 b aclamping rin 18 which screws intov the 1nternally threa ed end 016 95 4the retaining tube 14. This clamping ring is of such a length that.ifthe. lenses l2rand 13 are interchanged the ring cannot be screwed intoits bearingp From the foregoing it will be seen that the 1 13 difiersfrom, that of the lens-12,

front and rear. elements of improved-lens V systeni arenon-interchangeable owing to their difi'erence in diameter.

ribs and slots 11 of the frontv element different-ly from the spacing ofthe ribs and slots 11 of the rear'elementthe two sets of lenses pannotbe interchanged even though they were all of the same diameter. It willbe evident also that-my construction prevents ,reversal of the lenses ofeach element.

This applicationis a divisionof my copending application Serial No.249,223, filed January 25, 1928.

What I claim is 1. In projector apparatus the combination of a lensretaining ring, inwardly projecting unequally spaced members on saidring, a

pair of lenses provided with unequally spaced slots receiving saidprojections and corresponding with the unequal spacing thereof, aclamping ring for clamping said lenses in said retaining r ng, theunequal spacing of said projections, and said lens slots preventingreversal of the lenses.

2: In projector apparatus the combination of a lens retaining ring, alens having spaced slots in the periphery thereof, a clamping" 'ring forclamping said lens in the retaining ring, unequally spaced projectionsson the M inter or of said retaining ring, the spacing of the slots inthe periphery ofthe lens cor responding with the unequal spacing of theprojections on the interior of the retaining ring, said'slots andprojections cooperating forpositively positioningthe lens in the ringand, preventing its reversal.

- ,3. In projector apparatus the combination of a lens retaining ring,inwardly extending unequally spacedprojections on said ring, a lenshaving unequally spaced slots for receiving said projections, a'clamping ring, a

shoulder on said retaining ring against which the lens is clamped bysaid clamping ring; the said projections and lens slots preventingreversal pf the lens in the retaining ring.

\ 4-. In projector apparatus the combination ofa-palr of separablelenses, an internally shouldered retai iing tube for',receiving saidlenses, said retaining tube being "provided with .two sets of inwardlyextending projections, one set cooperating with one-of said of theprojections of the other set whereby lenses, the other set cooperatingwith the other of said lenses, the'spacing of theprojections of one setdiffering from the spacing transposing of the lenses in theretainingtube is prevented, and a clamping ring for holdingsaidllenses'against said shoulder.

This specification signed this 4 12 day of July, 1929. v

- i 1 .KARL KRUENING.

It is to be noted also that by spacing the"

